function Student(name, age, gender) {
	this.name = name;
	this.age = age;
	this.gender = gender;
}
Student.prototype = {
	constructor: Student,
	work: 'study',
	sayHi: function () {
		console.log('hi');
	}
};
Student.prototype.job = 'student';
var student = Student('zhangsan', 18, 'male');
for (let attr in student) {
	if (student.hasOwnProperty(attr)) {
		console.log(attr);
	}
}

function Father(name, age) {
	this.name = name;
	this.age = age;
}

function Son(name, age) {
	Father.call(this, name, age);
	this.hobby = 'study';
}

Son.prototype.__proto__ = Father.prototype;
Object.getPrototypeOf(Father);
Father.prototype.isPrototypeOf(Son.prototype);
